This invention relates to a method and apparatus for closing and sealing off the flow of liquids through a pipe or conduit and more particularly to a pneumatic sealing device to accomplish this result.
Various types and configurations of valves have been used to stop the flow of liquid through pipes. The most commonly used devices are manually operated valves which have input and output pipes connected to it. When the flow of the liquid is to be stopped, the valve is manually turned and seals off the flow of liquid past the valve. This configuration normally requires the pipe to be threaded and screwed into the valve assembly and thus the valve becomes integral with and connected to the input and output pipes. When the pipes are exposed, this design is satisfactory as access to the valve is normally quite easy. Even if the pipes are in a wall, this is still normally acceptable as the valve can be extended a short distance through the wall so that the flow of liquid can be stopped. However, the valve must normally be installed during the initial installation of the pipes as later installation becomes much more difficult, time consuming, and expensive. Large valves of this type can be motor operated from remote locations. However, such devices are normally expensive and used only in industrial applications.
In most residential buildings, the drains and sewage feed into a single sewage pipe which runs below the basement floor. This sewage pipe runs under the house and is connected to the municipal sewage system. There is normally a vertically rising pipe through the basement floor which leads into this sewage pipe and it is commonly referred to as a stand pipe or a clean out tee. The stand pipe provides limited access to the sewage pipe and from the basement to the outside sewage system. Thus, should there be an obstruction in the sewage pipes, a router-type cleaning device can be inserted through the stand pipe and snaked through the pipes to clean out tree roots or other debris which may be blocking the pipes.
During extremely heavy rains it is not uncommon for the municipal sewage system to be unable to accommodate the heavy flood rain waters. This causes the sewage pipes and system to completely fill which in turn causes the sewage to back up into the sewage pipes from individual residences. Without some means to prevent this back up, the basement will commonly flood.
One attempted solution to the problem is to supply a sump pump which will remove water from a sump placed in the basement. This may prove to be acceptable for removing water which is free of sewage, but generally is not designed for the removal of sewage having solid waste particles in it. Furthermore, it does not solve the problem of keeping the sewage from backing up into the house or the basement and the attendant unpleasant odors and solid particles from entering the basement, which must later be cleaned up.
It is not practical to install a valve at the junction of the sewage pipe and the stand pipe as the valve would probably block access of pipe cleaning routers should they be later required. Also, as the valve would probably be operated very infrequently, it might corrode in the opened position and not be operable when needed. Furthermore, a manually operated valve still requires a person to open and close it.
What is required is a valve system which would be selectively placed into the outside sewage pipe to seal off the flow of fluid when required and be easily removed for storage into the existing stand pipe when free fluid flow is desired.